# Terragrunt

> A configuration-as-code tool that wraps OpenTofu/Terraform to manage module deployments.

*Terragrunt* is a thin wrapper around OpenTofu/Terraform that provides configuration-as-code capabilities for managing infrastructure module deployments. It is developed by [Gruntwork](https://gruntwork.io/) and is free, open-source, and runs entirely locally.

In the Panfactum stack, Terragrunt is the primary tool for deploying all infrastructure modules. It is configured via `terragrunt.hcl` files in the environments directory.

Key capabilities that Terragrunt adds over plain OpenTofu:

- **Configuration sharing**: Share provider configurations, backend settings, and common inputs across modules
- **Version management**: Pin specific versions of both local and remote infrastructure modules
- **Inter-module dependencies**: Declare deployment order and chain outputs between modules
- **Secrets integration**: Integrates with [sops](https://github.com/getsops/sops) for encrypted secrets in configuration files
- **Retry logic**: Handles common intermittent provider and network failures automatically
- **Built-in functions**: Additional helper functions for constructing configuration values